"Apple's relentless pursuit of thinness and lightness"

That ended in the previous generation.

The 12" MacBook and previous-gen (final-gen Intel) MacBook pros were the most beautiful and the most thin/light MacBooks

With the new MB Pros, Apple went with much more compromise towards functionality and quality. I think they are almost flawless – just much more ugly than previous gen!

I am not sure about the Airs – and maybe that's your primary comparison.